Sparfloxacin of formula: ##STR2## as well as its addition salts with acids or bases, useful as antimicrobial agents, have been described in Patent Application EP 221,463.
Patent Application EP 284935 also describes quinolones and their salts and, amongst these products, sparfloxacin.
Unfortunately, the salts of sparfloxacin are generally insoluble or unstable in solution. It has thus not been possible until now to prepare suitable compositions for parenteral administration.
European Patent EP 322,892 mentions these difficulties and describes lyophilised compositions containing a salt of sparfloxacin with an acid. However, these compositions do not allow stable solutions to be obtained for a prolonged period and for this reason only the preparation of a solution to be used at once is possible. In addition, such solutions risk being unsuitable for use in slow perfusions.